The present invention relates generally to apparatus and methods for use when developing wound coils and, more particularly, to apparatus and methods for handling predetermined segments of magnet wire used for developing coils for dynamoelectric machines such as electric motors.
During one process for winding coils for dynamoelectric machines (e.g., electric motors) magnet wire is fed from a supply (e.g., a reel) along a predetermined path to a wire dispenser which is utilized during generation of winding turns for one or more coils in two or more coil groups which, subsequently, are disposed in slots of a magnetic core.
Periodically, a given wire supply becomes exhausted and the winding process is interrupted while the end of wire from a new or auxiliary supply is fed along the predetermined path before the winding process may be resumed. It will be appreciated that when equipment such as that shown for example in Pavesi U.S. Pat. No. 3,557,432, Hill et al U.S. Pat. No. 3,635,261, or Smith et al U.S. Pat. No. 3,742,596 (these patents being cited and incorporated herein for background purposes) is utilized, substantial amounts of capital will have been invested. In order to obtain a satisfactory return on such investment, it is extremely important that the output of such machines be maximized; and a corollary to this is that the down time for such machines should be minimized. Any excess time that machine utilization is interrupted to resupply wire is down time that should be avoided, if at all possible.
The predetermined path for wire in a coil winding machine usually is relatively long and complex (i.e. contorted) and it may take ten minutes or more to thread the end of a new wire supply through a complex piece of winding equipment. Usually, more complex winding equipment represents a greater investment. Unfortunately, it usually is this kind of equipment that requires a more complex wire path and therefore requires greater amounts of down time whenever a new supply of wire is fed into the machine. While relatively heavy wire is usually easier to supply through a series of wire tubes and guides, fine wire is usually so flexible that when attempts are made to push the fine wire through a contorted guide tube arrangement, the wire jams therein.
Thus, it will be understood that it would be desirable to provide new and improved methods and apparatus whereby magnet wire, and particularly magnet wire of relatively small diameter, may be quickly and easily threaded along a contorted guide tube arrangement to a wire dispensing mechanism.
One type of coil winding operation has become known as "wind and shed" or "shedder" winding, and may be carried out, for example, with equipment of the type illustrated in the above referenced related application or as illustrated for example in Cutler et al U.S. Pat. No. 3,522,650, Arnold U.S. Pat. No. 3,579,791, or Smith et al U.S. Pat. No. 3,742,596. This type of operation often is accomplished by holding a coil form assembly in a winding plane while turns of a first size are developed thereabout. Then, while turns continue to be generated, at least part of the form assembly is jumped axially relative to the winding plane and to a winding turn receiving mechanism. Alternatively, the receiving mechanism and coil forms may rotate; or the wire dispenser and receiving mechanism may be jumped relative to the coil form assembly. When any of the just mentioned approaches are followed, however, a plurality of winding turns will be generated in substantially one given plane. It has now been determined, and particularly for higher winding speeds (e.g. speeds at 2000 r.p.m. and higher), that wire being wound in a fixed winding plane about a coil form assembly may begin to oscillate and vibrate. One result of excessive oscillation is that the wire turns will not shed as smoothly and uniformly as might be desired. Accordingly, it would be desirable, and it is one of the objects of the present invention, to provide new and improved apparatus and methods whereby problems associated with excessive wire vibrations or oscillations in a winding plane may be overcome.
When at least two coil groups ("coil group" also being referred to as "poles" in published literature) are formed in a turn receiving mechanism prior to transfer to a magnetic core structure, a more common approach is to develop a first coil group in the mechanism or receiver, index the receiver, and then wind a second plurality of turns so that a second pole is established in the receiver. It will be understood that the winding direction (e.g., flyer rotation) may be reversed from one pole to the next. Moreover, it will be understood that the receiver may be indexed in either a clockwise or counterclockwise direction about its longitudinal center. In any of these cases, it would be desirable to provide a mechanism and method whereby a segment of an interpole lead wire is grasped as one pole is being indexed in the receiver, an extra segment of wire is pulled from the wire dispenser, and the grasped segment is released after at least some turns for a subsequent pole have been generated. The assignee of the present application has used in its regular commercial production, at least since January, 1973, and in conjunction at least with equipment of the type illustrated in the above referenced U.S. Pat. No. 3,579,791, a mechanism which would clasp a wire segment after a first pole had been developed and release such segment after at least some turns of a second pole had been developed. The device that has been so used, and thus constitutes prior art insofar as the present application is concerned, included a first structure that was movably mounted to a base. The first structure was mounted for sliding movement along a horizontally disposed slide, and a second end of the first structure was connected to the piston of an air cylinder which in turn was fastened to the base. A first end of the first structure pivotally mounted a clasping member which was mounted for rotation, about the pivot, relative to the first structure. A second air cylinder was mounted to the first structure, and the piston of the second air cylinder was connected to the clasping member to cause rotation of a portion thereof through an arcuate path.
Devices of the type just described have been found to be limited in actual practice. Accordingly, it would be desirable to provide new and improved devices and methods for handling interpole wire segments so that an extra or additional length of wire may be pulled from a wire supply while a winding turn receiver is indexed so that an interpole wire segment of adaquate length may be provided.
Accordingly, it is a general object of the present invention to provide new and improved methods and apparatus for handling segments of wire that interconnect coil groups (or poles) that are disposed in a winding turn receiver.
It is another general object of the present invention to provide new and improved methods and apparatus that include provisions for feeding a magnet wire end through a contorted guide tube arrangement.
It is yet another general object of the present invention to provide new and improved methods and apparatus for controlling oscillations of wire segments across a winding plane while winding turns are being generated along such plane.